Power Guidelines, Power Type Guidelines | Cisco Systems OL-23089-01

Chapter 2 Preparing to Install the Cisco Unified IP Phone on Your Network

Providing Power to the Phone

Power Guidelines

Table 2-1provides guidelines that apply to external power and to PoE power for the Cisco Unified IP Phones 7931G.

Table 2-1 Guidelines for Powering the Cisco Unified IP Phones 7931G

	Power Type	Guidelines

	External power—	The CP-PWR-CUBE-3 external power supply may be used with the
	Provided through a Cisco	Cisco Unified IP Phones 7931G.
	external power supply.

	External power—Provided	The Cisco Unified IP Phone Power Injector may be used with any
	through the Cisco Unified	Cisco Unified IP Phone. Functioning as a midspan device, the injector
	IP Phone Power Injector.	delivers inline power to the attached phone. The Cisco Unified IP Phone
		Power Injector is connected between a switch port and the IP Phone, and
		supports a maximum cable length of 100m between the unpowered switch
		and the phone.

	PoE power—Provided by	• The Cisco Unified IP Phones 7931G supports IEEE 802.3af Power
	a switch through the	over Ethernet.
	Ethernet cable attached to	• To ensure uninterruptible operation of the phone, make sure that the
	the phone.
	the phone.	switch has a backup power supply.
		switch has a backup power supply.
		• Make sure that the CatOS or IOS version running on your switch
		supports your intended phone deployment. Refer to the
		documentation for your switch for operating system version
		information.

For related information about power, refer to these documents:

•Cisco Catalyst Switches—Cisco switches that work with the Cisco Unified IP Phones:

http://www.cisco.com/en/US/products/hw/switches/ps708/tsd_products_support_series_home.htm l

•Cisco IOS Software—Cisco IOS releases that support bidirectional power negotiation:

http://www.cisco.com/en/US/products/sw/iosswrel/products_ios_cisco_ios_software_category_ho me.html

•Other requirements and restrictions regarding power:

–Cisco Unified IP Phone Power Injector Installation Guide

–Power Over Ethernet Solutions—Introduction

–Integrated Service Routers: http://www.cisco.com/en/US/products/hw/routers/index.html

Cisco Unified IP Phone 7931G Administration Guide for Cisco Unified Communications Manager 8.5 (SCCP and SIP)

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